Avaya this week announced plans to acquire Ubiquity Software, a maker of SIP-based applications and software development tools, for around $144 million.

Ubiquity, based in Cardiff, Wales, makes SIP-based application servers used by carriers to develop and deploy IP Multimedia Subsystems (IMS). With IMS technology, carriers can provide converged wired and wireless telephony, or fixed-mobile convergence (FMC) services.

Avaya, whose customer base is composed mostly of enterprises, did not say what specific plans it has for Ubiquity's carrier-focused SIP application server products. If the deal goes through, the acquisition could give Avaya better technology for delivering enterprise FMC products. Avaya has started to pursue FMC aggressively as of late to keep up with FMC-related acquisitions and partnerships made by Cisco. In November, Avaya spent $15 million to acquire Traverse Networks, which makes cell phone/VoIP convergence products.

Ubiquity was founded in 1993 and has around 220 employees worldwide. According to the company, its customers consist of carriers, independent software vendors, and service provider channel partners in Europe, Canada and Asia. British Telecom is among its largest users.